Carburetor



INVENTOR.

ATTORNEY May 16, 1961 A. H. WINKLER CARBURETOR Filed Aug. 31, 1959 ALBERT H. WINKLER United States Patent O CARBURETOR Albert H. Winkler, Elmira, N.Y., assignor to The Bendix Corporation, a corporation of Delaware Filed Aug. 31, 1959, Ser. No. 837,267

2 Claims. (Cl. 261-64) l The present invention relates generally to carburetors for internal combustion engines and more particularly to a choke valve for such carburetors.

The progressive lowering of the hood lines of modern automobiles has imposed and continues to impose increasingly severe limitations on the height of carburetors. In

p a conventional downdraft carburetor a choke valve is of the fuel and air. The present invention does away with the airhorn by locating the choke valve in the main body adjacent the small venturi. In comparison with a conventional carburetor the present invention increases the air ilow through the small venturi during low flow operation with the choke closed or partially closed. The increased air ilow through the small venturi improves atomization of the fuel.

It is an object `of the present invention to provide a choke valve having a construction such as to ettect an overall reduction in the height of the carburetor.

It is a further object of the present invention to provide a choke valve construction to provide better atomization of fuel at relatively low air ilows.

Other objects and advantages of the present invention will become apparent lfrom the following description and accompanying drawings in which:

Figure l is a vertical sectional view of a carburetor embodying the present invention; and

Figure 2 is a top view of the carburetor shown in Figure l.

Referring now to the drawings and more particularly to Figure 1, numeral designates a carburetor having a main body 12, a throttle body 14 and a float bowl 16. The interior walls 18 and 20 of the main body and throttle body respectively form `an induction passage designated generally by numeral 22. A main venturi 24 is located in induction passage 22 and is formed integrally with the walls 1S and 20. A small venturi 26 is located in induction passage 22 anterior the main venturi 24 and is adapted to discharge substantially at the throat of the main venturi. Small venturi 26 is held in position by a bracket or rib 28 which projects from the interior wall 18 of the main body. Rib 28 also carries the main discharge jet 30 which is connected to the float bowl 16 through a metering restriction 32. The main discharge jet 30 is disposed to discharge substantially at the throat of the small venturi 26. Rib 28 also carries air bleed 34 which through chamber 36 and branch conduits 38 and 40 is adapted to bleed air into the main discharge jet 30. Bleed 34 is located downstream of the choke valve 52 so that when the choke valve is closed the vacuum in passage 22 causes fuel to be discharged through bleed 34.

2,984,466 Patented May 16, 1961 ICE A tapped bore 42 formed in upwardly extending boss 44 is provided to threadedly receive the mounting bolts of an appropriate air cleaner (not shown).

Carburetor 10 is provided with a conventional idle system, a portion of which is shown at 46. A throttle valve 48 is mounted in induction passage 22 on a throttle shaft 50 which is journalled in the walls ofthe throttle body 14.

A choke valve 52 is mounted in induction passage 22 on a choke shaft 54 which is journalled in the walls of main body 12. The choke shaft is located in the induction passage adjacent to but offset from the anterior edge of the small venturi 26 as best seen in Figure 1.

As best seen in Figure 2 the choke valve 52 is cut out to form a notch or opening 56 which is shaped to receive the small venturi 26 and bracket 28 when the choke valve 52 is in its closed position. 'Ihus when the choke valve 52 is closed the entire air flow through induction passage 22 is directed through small venturi 26.

A cylinder 58 is mounted on the main body containing a vacuum responsive piston 60 which is connected to the choke valve 52 by means of rod 62 and bracket 64. Cylinder 58 is connected to induction passage 22 downstream of throttle valve 48 by means of conduit 66. A housing 68 is mounted on main body 12 containing a thermostat 70 which has a yone-way connection with choke shaft 54 through lever 72. Housing 68 is adapted to be connected to a source of heated air (not shown) by means of conduit 74. Housing 68 is also connected to the induction passage downstream of throttle valve 48 by a conduit (not shown).

As shown in the drawings choke valve 52 is unbalanced and when the choke valve is open the portion thereof having the longest radius extends downstream of the anterior edge of the small venturi. It is also to be noted in the drawings that when the choke valve is open it extends substantially parallel to the outside wall of the small venturi 26 to act as a vane to improve the air flow distribution in the carburetor. The location and construction of choke valve 52 is such that the conventional airhorn may be eliminated and the overall height of the carburetor reduced substantially. Furthermore, when the choke valve is closed all of the air flow through the induction passage 22 is directed through the small venturi 26 thereby increasing the velocity of air ilow and thus providing for good atomization of the fuel discharged into the induction passage. The control of the choke valve by means of thermostat 70, vacuum piston 60 and air ilow acting on the unbalanced portion of choke valve 52 is Well known to persons skilled in the art.

Although a particular embodiment of my invention has been described it will be understood by those skilled in the art that the objects of the invention may be attained by the use of `constructions different in certain respects from that disclosed with-out departing from the underlying principles of the invention.

I claim:

l. In a carburetor, an induction passage, a main venturi in said passage, a small venturi. bracket means securing said small venturi to the wall of said passage in a position whereby said small venturi discharges into said main ven turi, at least a portion of said small venturi being disposed in said passage anterior to said main venturi, a choke shaft in said passage adjacent to but offset from the anterior edge of said small venturi, an unbalanced choke valve mounted on said choke shaft and means defining a notch in said choke valve, said notch being shaped to receive said small venturi, said choke valve being rotatable from an open position wherein a portion of said choke valve is adjacent to said small venturi and substantially parallel to the flow axis therethrough to a closed position wherein said choke valve is transverse said passage to permit air flow only through said small venturi.

2. In a carburetor, a main body having interior walls dening an induction passage, a main venturi formed by said walls, a small venturi disposed to discharge substantially at the throat of said main venturi, bracket means connecting said small venturi to the Wall of said main body, a choke shaft mounted in said body and extending transverse said passage adjacent to and oifset from an anterior edge of said small venturi, an unbalanced choke Valve mounted on said shaft, and a radially extending slot lformed in said valve, said slot opening at one edge of said valve and being shaped to receive said small venturi and bracket when said valve is in closed position, said 5 said passage except for said small venturi.

References Cited in the le of this patent UNITED STATES PATENTS Leibing Dec. 28, 1948 2,752,131 Gretz June 26, 1956 

